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<head><meta charset="utf-8"><title>I-prioritize #70924 &#x27;rustc&#x27; panicked at &#x27;failed to lookup `S · t-compiler/wg-prioritization · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/index.html">t-compiler/wg-prioritization</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html">I-prioritize #70924 &#x27;rustc&#x27; panicked at &#x27;failed to lookup `S</a></h3>

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<a name="196748490"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196748490" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> triagebot <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196748490">(May 07 2020 at 09:53)</a>:</h4>
<p><span class="user-group-mention" data-user-group-id="2403">@WG-prioritization</span> issue <a href="https://github.com/rust-lang/rust/issues/70924" title="https://github.com/rust-lang/rust/issues/70924">#70924</a> has been requested for prioritization.</p>



<a name="196759070"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196759070" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> o0Ignition0o - Jeremy Lempereur <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196759070">(May 07 2020 at 11:48)</a>:</h4>
<p><code>it seems like cargo clean fixed it though</code><br>
Ok so it seems to break build caches, but cargo clean is a workaround.</p>



<a name="196759299"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196759299" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> o0Ignition0o - Jeremy Lempereur <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196759299">(May 07 2020 at 11:51)</a>:</h4>
<p>I feel like this kind of regressions could be caught automatically.<br>
Anyway, the issue is not critical as in "nobody can use rust anymore" but it will probably cause a lot of efforts for project maintainers to figure out what happened, and quite a bit of compute minutes to fully clean their CI caches. <br>
I'd go for <code>P-High</code> or <code>P-Medium</code></p>



<a name="196759376"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196759376" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Léo Lanteri Thauvin <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196759376">(May 07 2020 at 11:52)</a>:</h4>
<p>Mhh, it would be great to bisect this</p>



<a name="196759404"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196759404" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Léo Lanteri Thauvin <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196759404">(May 07 2020 at 11:52)</a>:</h4>
<p><span class="user-mention" data-user-id="133247">@bjorn3</span> Is your bisect bot available?</p>



<a name="196759455"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196759455" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Léo Lanteri Thauvin <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196759455">(May 07 2020 at 11:53)</a>:</h4>
<p>If this is a beta regression, I’d say <code>P-high</code> to try to fix this before it hits stable</p>



<a name="196770413"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196770413" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Santiago Pastorino <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196770413">(May 07 2020 at 13:34)</a>:</h4>
<p>I'd say that this is at least <code>P-high</code></p>



<a name="196770464"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196770464" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Santiago Pastorino <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196770464">(May 07 2020 at 13:34)</a>:</h4>
<p>seems like a bunch of people are hitting this issue</p>



<a name="196771081"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196771081" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Santiago Pastorino <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196771081">(May 07 2020 at 13:39)</a>:</h4>
<p><span class="user-mention silent" data-user-id="218578">o0Ignition0o - Jeremy Lempereur</span> <a href="#narrow/stream/227806-t-compiler.2Fwg-prioritization/topic/I-prioritize.20.2370924.20'rustc'.20panicked.20at.20'failed.20to.20lookup.20.60S/near/196759299" title="#narrow/stream/227806-t-compiler.2Fwg-prioritization/topic/I-prioritize.20.2370924.20'rustc'.20panicked.20at.20'failed.20to.20lookup.20.60S/near/196759299">said</a>:</p>
<blockquote>
<p>I feel like this kind of regressions could be caught automatically.<br>
Anyway, the issue is not critical as in "nobody can use rust anymore" but it will probably cause a lot of efforts for project maintainers to figure out what happened, and quite a bit of compute minutes to fully clean their CI caches. <br>
I'd go for <code>P-High</code> or <code>P-Medium</code></p>
</blockquote>
<p>I have a different feeling, this seems to be hitting a lot of codebases, yeah there's a workaround as probably are workarounds for everything but in my opinion this is <code>P-high</code> or <code>P-critical</code>, I'm leaning a bit more towards <code>P-critical</code></p>



<a name="196773743"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196773743" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> o0Ignition0o - Jeremy Lempereur <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196773743">(May 07 2020 at 13:57)</a>:</h4>
<p>ok, that would make sense as well yeah</p>



<a name="196817097"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196817097" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Léo Lanteri Thauvin <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196817097">(May 07 2020 at 19:08)</a>:</h4>
<p>Even if there is a workaround, it’s still frustrating to have to delete the cache and do a full compilation, and I guess this is especially true in Rust</p>



<a name="196894605"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196894605" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Santiago Pastorino <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196894605">(May 08 2020 at 13:23)</a>:</h4>
<p>but also people may not know they need to delete the cache</p>



<a name="196894639"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196894639" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Santiago Pastorino <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196894639">(May 08 2020 at 13:23)</a>:</h4>
<p>I think it's good to wait a bit until we see a repro before prioritizing this one</p>



<a name="196894705"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196894705" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Santiago Pastorino <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196894705">(May 08 2020 at 13:24)</a>:</h4>
<p>or we could even give kind of a temporary priority until is clear, whatever the rest prefer is fine to me</p>



<a name="196906865"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196906865" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Léo Lanteri Thauvin <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196906865">(May 08 2020 at 15:06)</a>:</h4>
<p>I believe it’s a good idea to assign a high priority to issues that need bisection/MCVE</p>



<a name="196906899"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196906899" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Léo Lanteri Thauvin <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196906899">(May 08 2020 at 15:07)</a>:</h4>
<p>I think it might help give those issues the visibility they need</p>



<a name="196906968"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196906968" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> simulacrum <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196906968">(May 08 2020 at 15:07)</a>:</h4>
<p>I think we should put a high priority after bisection/MCVE, ideally that's not something we'd push compiler team members to do I think</p>



<a name="196906977"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196906977" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Léo Lanteri Thauvin <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196906977">(May 08 2020 at 15:07)</a>:</h4>
<p>But I might be wrong, I don’t know if many people look for the high-priority issues first</p>



<a name="196907056"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/196907056" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> simulacrum <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#196907056">(May 08 2020 at 15:08)</a>:</h4>
<p>but obviously if e.g. that's not happening then yeah</p>



<a name="197200183"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/197200183" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Santiago Pastorino <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#197200183">(May 11 2020 at 20:25)</a>:</h4>
<p>this one has now a repro</p>



<a name="197200442"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/197200442" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Santiago Pastorino <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#197200442">(May 11 2020 at 20:28)</a>:</h4>
<p>I'm still debating between <code>P-critical</code> and <code>P-high</code></p>



<a name="197436108"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/197436108" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Santiago Pastorino <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#197436108">(May 13 2020 at 16:10)</a>:</h4>
<p>this is the last one without priority, assigning <code>P-high</code> given that seems to be more consensus on that</p>



<a name="197436147"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize%20%2370924%20%27rustc%27%20panicked%20at%20%27failed%20to%20lookup%20%60S/near/197436147" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> triagebot <a href="https://rust-lang.github.io/zulip_archive/stream/227806-t-compiler/wg-prioritization/topic/I-prioritize.20.2370924.20&#x27;rustc&#x27;.20panicked.20at.20&#x27;failed.20to.20lookup.20.60S.html#197436147">(May 13 2020 at 16:10)</a>:</h4>
<p>Issue <a href="https://github.com/rust-lang/rust/issues/70924">#70924</a>'s prioritization request has been removed.</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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